1. Field of the Invention
This invention is in the field of smelting ore concentrates, particularly sulfide type materials wherein the ore concentrate is smelted with relatively pure oxygen in a cyclone smelter, followed by an aftertreatment in which the smelt is reduced to produce the metal as a molten layer with an overlying slag layer, the conditions of aftertreatment being carefully controlled to improve the efficiency of the overall process, and to reduce the amount of metal that is left in the slag.
2. Description of the Prior Art
In German OS No. 2,348,105 there is described a method in which fine-grained sulfur-containing ore concentrates are introduced into a cyclone reactor into which an oxygen-rich gas is blown through a tangentially discharging supply line. The ore concentrate is continuously calcined and melted in the cyclone reactor in the turbulent conditions existing in the reactor. The smelt is collected below the cyclone reactor and consists of a lighter slag phase and a heavier metal phase such as copper matte. The smelt is then metallurgically aftertreated by means of reducing gases which are blown onto the smelt through a lance so that metal oxides which are contained in the slag phase are converted into droplets of metal matte. With such an aftertreatment with reducing gases under these conditions, the lighter slag phase still contains relatively large amounts of metal in admixture with the smelt, so that the two mixed phases are withdrawn to another location where they are subsequently separated from each other by means of a separate centrifuge. Beyond the reduction of the oxides, no other aftertreatment of the melt is carried out.